Z-styryl sulfone treatment of proliferative diseases

ABSTRACT

(Z)-styryl benzylsulfones of formula I are useful as anticancer agents:whereinR1 is selected from the group consisting of hydrogen, chloro and nitro;R2 is selected from the group consisting of hydrogen, lower alkyl, lower alkoxy, chloro, bromo, and fluoro; andR3 and R4 are independently selected from the group consisting of hydrogen, lower alkyl, nitro, chloro, bromo, and fluoro;provided that at least one of R1 or R2 is hydrogen.The corresponding (Z)-styryl benzylsulfides are useful as intermediates in the preparation of the biologically active (Z)-styryl benzyl sulfones.

This is a divisional of application Ser. No. 09/282,855 filed Mar. 31,1999, now U.S. Pat. No. 6,201,154.

FIELD OF THE INVENTION

The invention relates to compositions and methods for the treatment ofcancer.

BACKGROUND OF THE INVENTION

Extracellular signals received at transmembrane receptors are relayedinto the cells by the signal transduction pathways (Pelech et al.,Science 257:1335 (1992)) which have been implicated in a wide array ofphysiological processes such as induction of cell proliferation,differentiation or apoptosis (Davis et al., J. Biol. Chem. 268:14553(1993)). The Mitogen Activated Protein Kinase (MAPK) cascade is a majorsignaling system by which cells transduce extracellular cues intointracellular responses (Nishida et al., Trends Biochem. Sci. 18:128(1993); Blumer et al., Trends Biochem. Sci. 19:236 (1994)). Many stepsof this cascade are conserved, and homologous for MAP kinases have beendiscovered in different species.

In mammalian cells, the Extracellular-Signal-Regulated Kinases (ERKs),ERK-1 and ERK-2 are the archetypal and best-studied members of the MAPKfamily, which all have the unique feature of being activated byphosphorylation on threonine and tyrosine residues by an upstream dualspecificity kinase (Posada et al., Science 255:212 (1992); Biggs III etal., Proc. Natl. Acad. Sci. USA 89:6295 (1992); Garner et al., GenesDev. 6:1280 (1992)).

Recent studies have identified an additional subgroup of MAPKs, known asc-Jun NH2-terminal kinases 1 and 2 (JNK-1 and JNK-2), that havedifferent substrate specificities and are regulated by different stimuli(Hibi et al., Genes Dev. 7:2135 (1993)). JNKs are members of the classof stress-activated protein kinases (SPKs). JNKs have been shown tobectivated by treatment of cells with UV radiation, pro-inflammatorycytokines and environmental stress (Derijard et al., Cell 1025 (1994)).The activated JNK binds to the amino terminus of the c-Jun protein andincreases the protein's transcriptional activity by phosphorylating itat ser63 and ser73 (Adler et al., Proc. Natl. Acad. Sci. USA 89:5341(1992); Kwok et al., Nature 370:223 (1994)).

Analysis of the deduced primary sequence of the JNKs indicates that theyare distantly related to ERKs (Davis, Trends Biochem. Sci. 19:470(1994)). Both ERKs and JNKs are phosphorylated on Tyr and Thr inresponse to external stimuli resulting in their activation (Davis,Trends Biochem. Sci. 19:470 (1994)). The phosphorylation (Thr and Tyr)sites, which play a critical role in their activation are conservedbetween ERKs and JNKs (Davis, Trends Biochem. Sci. 19:470 (1994)).However, these sites of phosphorylation are located within distinct dualphosphorylation motifs: Thr-Pro-Tyr (JNK) and Thr-Glu-Tyr (ERK).Phosphorylation of MAPKs and JNKs by an external signal often involvesthe activation of protein tyrosine kinases (PTKs) (Gille et al., Nature358:414 (1992)), which constitute a large family of proteinsencompassing several growth factor receptors and other signaltransducing molecules.

Protein tyrosine kinases are enzymes which catalyze a well definedchemical reaction: the phosphorylation of a tyrosine residue (Hunter etal., Annu Rev Biochem 54:897 (1985)). Receptor tyrosine kinases inparticular are attractive targets for drug design since blockers for thesubstrate domain of these kinases is likely to yield an effective andselective antiproliferative agent. The potential use of protein tyrosinekinase blockers as antiproliferative agents was recognized as early as1981, when quercetin was suggested as a PTK blocker (Graziani et al.,Eur. J. Biochem. 135:583-589 (1983)).

The best understood MAPK pathway involves extracellular signal-regulatedkinases which constitute the Ras/Raf/MEK/ERK kinase cascade (Boudewijnet al., Trends Biochem. Sci. 20, 18 (1995)). Once this pathway isactivated by different stimuli, MAPK phosphorylates a variety ofproteins including several transcription factors which translocate intothe nucleus and activate gene transcription. Negative regulation of thispathway could arrest the cascade of these events.

What are needed are new anticancer chemotherapeutic agents which targetreceptor tyrosine kinases and which arrest the Ras/Raf/MEK/ERK kinasecascade. Oncoproteins in general, and signal transducing proteins inparticular, are likely to be more selective targets for chemotherapybecause they represent a subclass of proteins whose activities areessential for cell proliferation, and because their activities aregreatly amplified in proliferative diseases.

SUMMARY OF THE INVENTION

It is an object of the invention to provide compounds, compositions andmethods for the treatment of cancer and other proliferative diseases.The biologically active compounds are in the form of (Z)-styrylbenzylsulfones.

It is a further object of the invention to provide intermediates usefulfor the preparation of compounds having anticancer activity. Theintermediates comprise (Z)-styryl benzylsulfides.

The present invention provides for pharmaceutical compositionscomprising a pharmaceutically acceptable carrier and one or morecompounds of the formula I

wherein

R₁ is selected from the group consisting of hydrogen, chloro and nitro;

R₂ is selected from the group consisting of hydrogen, lower alkyl, loweralkoxy, chloro, bromo, and fluoro; and

R₃ and R₄ are independently selected from the group consisting ofhydrogen, lower alkyl, nitro, chloro, bromo, and fluoro;

provided at least one of R₁ or R₂ is hydrogen.

According to one preferred embodiment of the invention, pharmaceuticalcompositions of compounds of formula I are provided wherein R₁ ishydrogen. More preferably, R₁ and R₃ are hydrogen, and R₂ and R₄ areindependently selected from the group consisting of chloro, fluoro andbromo.

According to another embodiment of the invention, novel compounds offormula I are provided where R₁, R₂, R₃ and R₄ are defined as above,provided:

(a) at least one of R₁ or R₂ is hydrogen;

(b) R₃ and R₄ may not both be hydrogen when:

(i) R₁ and R₂ are both hydrogen,

(ii) R₁ is chloro and R₂ is hydrogen, or

(iii) R₂ is chloro and R₁ is hydrogen; and

(c) when R₃ is hydrogen and R₄ is methyl:

(i) both R₁ and R₂ may not be hydrogen,

(ii) R₁ may not be chloro when R₂ is hydrogen, and

(iii) R₂ may not be chloro when R₁ is hydrogen.

Preferably, R₁ is hydrogen in the novel compounds of the invention.

According to another embodiment of the invention, novel (Z)-styrylbenzylsulfides are provided which are useful as intermediates in thepreparation of the biologically active (Z)-styryl benzylsulfones. The(Z)-styryl benzylsulfides have the formula:

wherein:

R₁ is selected from the group consisting of hydrogen, chloro and nitro;

R₂ is selected from the group consisting of hydrogen, lower alkyl, loweralkoxy, chloro, bromo, and fluoro, provided that at least one of R₁ orR₂ is hydrogen;

R₃ and R₄ are independently selected from the group consisting ofhydrogen, lower alkyl, nitro, chloro, bromo, and fluoro; provided:

(a) at least one of R₁ or R₂ is hydrogen;

(b) R₃ and R₄ may not both be hydrogen when:

(i) R₁ and R₂ are both hydrogen,

(ii) R₁ is chloro and R₂ is hydrogen, or

(iii) R₂ is chloro and R₁ is hydrogen; and

(c) when R₃ is hydrogen and R₄ is methyl:

(i) both R₁ and R₂ may not be hydrogen,

(ii) R₁ may not be chloro when R₂ is hydrogen, and

(iii) R₂ may not be chloro when R₁ is hydrogen.

Preferably, R₁ is hydrogen in the aforementioned intermediates.

By “lower alkyl” is meant straight or branched chain alkyl containingfrom one to six carbon atoms. The preferred alkyl group is methyl. By“lower alkoxy” is meant straight or branched chain alkoxy containingfrom one to six carbon atoms. The preferred alkoxy group is methoxy.

According to another embodiment of the invention, a method of treatingan individual for cancer or other proliferative disorder is provided,comprising administering to said individual an effective amount of theaforesaid pharmaceutical composition.

In another embodiment, a method of inhibiting growth of tumor cells inan individual afflicted with cancer is provided, comprisingadministering to said individual an effective amount of the aforesaidpharmaceutical composition.

In another embodiment, a method of inducing apoptosis of cancer cells,more preferably tumor cells, in an individual afflicted with cancer isprovided, comprising administering to said individual an effectiveamount of the aforesaid pharmaceutical composition.

DETAILED DESCRIPTION OF THE INVENTION

According to the present invention, certain (Z)-styryl sulfonederivatives selectively kill various tumor cell types without killingnormal cells. Without wishing to be bound by any theory, it is believedthat the compounds affect the MAPK signal transduction pathway, therebyaffecting tumor cell growth and viability. This cell growth inhibitionis associated with regulation of the ERK and JNK types of MAPK.

The compounds of the invention have been shown to inhibit theproliferation of various tumor cells by inducing cell death. Thecompounds are effective against a broad range of tumor types, includingbut not limited to the following: breast, prostate, ovarian, lung, brain(i.e, glioma) and renal. The compounds are also effective againstleukemic cells. The compounds do not kill normal cells in concentrationsat which tumor cells are killed.

Treatment of this broad range of tumor cells with the styryl sulfonecompounds of the invention leads to inhibition of cell proliferation andinduction of apoptotic cell death. In breast tumors, the effect isobserved for estrogen receptor (ER) positive as well as estrogenreceptor negative cells.

Tumor cells treated with the compounds of the invention accumulate inthe G2/M phase of the cell cycle. As the cells exit the G2/M phase, theyappear to undergo apoptosis. Treatment of normal cells with the styrylsulfones does not result in apoptosis.

Both cells treated with the styryl sulfone compounds of the inventionand untreated cells exhibit similar levels of intracellular ERK-2, butthe biochemical activity of ERK-2, as judged by its ability tophosphorylate the substrate myelin basic protein (MBP), is considerablydiminished in drug-treated cell compared to untreated cells. Withoutwishing to be bound by any theory, these results suggest that the styrylsulfones of the present invention block the phosphorylating capacity ofERK-2.

The styryl sulfones of the present invention enhance the ability of JNKto phosphorylate c-Jun protein compared to mock-treated cells. Withoutwishing to be bound by any theory, this result suggests that the styrylsulfones may be acting like pro-inflammatory cytokines or UV light,activating the JNK pathway, which in turn may switch on genesresponsible for cell growth inhibition and apoptosis.

Synthesis of (Z)-Styryl Sulfones

The compounds of the present invention were prepared by syntheticmethods yielding pure compounds in the (Z)-isomeric configuration. Thus,the nucleophilic addition of the appropriate thiols to substitutedphenylacetylene with subsequent oxidation of the resulting sulfide byhydrogen peroxide yields the Z-styryl sulfone. The procedure isgenerally described by Reddy et al., Sulfur Letters 13:83 (1991), theentire disclosure of which is incorporated herein as a reference.

The compounds are named according to the Cahn-Ingold-Prelog system, theIUPAC 1974 Recommendations, Section E: stereochemistry, in Nomenclatureof Organic Chemistry, Pergamon, Elmsford, N.Y., 1979 (the “Blue Book”).

In the first step of the synthesis, the sodium salt of benzyl mercaptanor the appropriate substituted benzyl mercaptan is allowed to react withphenylacetylene or the appropriate substituted phenylacetylene formingthe pure Z-isomer of the corresponding styryl benzylsulfide in goodyield.

In the second step of the synthesis, the (Z)-styryl benzylsulfideintermediate is oxidized to the corresponding sulfone in the pureZ-isomeric form by treatment with hydrogen peroxide.

General Procedure for the Synthesis of (Z)-Styryl Benzylsulfones

A. Synthesis of Intermediate Sulfides

To a refluxing methanolic solution of substituted or unsubstitutedsodiumbenzylthiolate prepared from 460 mg (0.02 g atom) of (i) sodium,(ii) substituted or unsubstituted benzyl mercaptan (0.02 mol) and (iii)80 ml of absolute methanol, is added freshly distilled substituted orunsubstituted phenylacetylene. The mixture is refluxed for 20 hours,cooled and then poured on crushed ice. The crude product is filtered,dried and recrystalized from methanol or aqueous methanol to yield apure (Z)-styryl benzylsulfide.

B. Synthesis of Sulfone

An ice cold solution of a (Z)-styryl benzylsulfide (3.0 g) in 30 ml ofglacial acetic acid is treated with 7.5 ml of 30% hydrogen peroxide. Thereaction mixture is refluxed for 1 hour and then poured on crushed ice.The separated solid is filtered, dried, and recrystalized from2-propanol to yield the pure (Z)-styryl benzylsulfone. The purity of thecompounds is ascertained by thin layer chromatography and geometricalconfiguration is assigned by analysis of infrared and nuclear magneticresonance spectral data.

Therapeutic Administration

The styryl sulfones of the invention may be administered in the form ofa pharmaceutical composition, in combination with a pharmaceuticallyacceptable carrier. The active ingredient in such formulations maycomprise from 0.1 to 99.99 weight percent. By “pharmaceuticallyacceptable carrier” is meant any carrier, diluent or excipient which iscompatible with the other ingredients of the formulation and todeleterious to the recipient.

The compounds of the invention may be administered to individuals(mammals, including animals and humans) afflicted with breast orprostate cancer. The compounds may be administered by any route,including oral and parenteral administration. Parenteral administrationincludes, for example, intravenous, intramuscular, intraarterial,intraperitoneal, intranasal, rectal, or subcutaneous administration. Theactive agent is preferably administered with a pharmaceuticallyacceptable carrier selected on the basis of the selected route ofadministration and standard pharmaceutical practice.

The active agent may be formulated into dosage forms according tostandard practices in the field of pharmaceutical preparations. SeeGennaro Alphonso, ed., Remington's Pharmaceutical Sciences, 18th Ed.,(1990) Mack Publishing Co., Easton, Pa. Suitable dosage forms maycomprise, for example, tablets, capsules, solutions, parenteralsolutions, troches, suppositories, or suspensions.

For parenteral administration, the active agent may be mixed with asuitable carrier or diluent such as water, an oil, saline solution,aqueous dextrose (glucose) and related sugar solutions, or a glycol suchas propylene glycol or polyethylene glycol. Solutions for parenteraladministration preferably contain a water soluble salt of the activeagent. Stabilizing agents, antioxidizing agents and preservatives mayalso be added. Suitable antioxidizing agents include sulfite, ascorbicacid, citric acid and its salts, and sodium EDTA. Suitable preservativesinclude benzalkonium chloride, methyl- or propyl-paraben, andchlorbutanol.

For oral administration, the active agent may be combined with one ormore solid inactive ingredients for the preparation of tablets,capsules, or other suitable oral dosage forms. For example, the activeagent may be combined with carboxymethylcellulose calcium, magnesiumstearate, mannitol and starch, and then formed into tablets byconventional tableting methods.

The specific dose of compound according to the invention to obtaintherapeutic benefit will, of course, be determined by the particularcircumstances of the individual patient including, the size, weight, ageand sex of the patient, the nature and stage of the disease, theaggressiveness of the disease, and the route of administration. Forexample, a daily dosage of from about 0.05 to about 50 mg/kg/day may beutilized. Higher or lower doses are also contemplated.

The practice of the invention is illustrated by the followingnon-limiting examples.

EXAMPLE 1 Z-Styryl Benzylsulfone

A solution of phenylacetylene (0.02 mol) and benzyl mercaptan (0.02 mol)and metallic sodium (0.02 g atom) was subjected to the GeneralProcedure, part A, to form Z-styryl benzylsulfide. The title compoundwas obtained in 65% yield by oxidation of the sulfide according to theGeneral Procedure, part B. ¹HNMR (CDCl₃) δ 4.50 (2H, s), 6.65 (1H, d,J_(H,H)=11.2), 7.18-7.74 (10H aromatic+1H ethylenic).

EXAMPLE 2 Z-Styryl 4-Chlorobenzylsulfone

A solution of phenylacetylene (0.02 mol) and 4-chlorobenzyl mercaptan(0.02 mol) and metallic sodium (0.02 g atom) was subjected to theGeneral Procedure to form Z-styryl 4-chlorobenzylsulfide. The titlecompound was obtained in 72% yield following oxidation. ¹HNMR (CDCl₃) δ4.56 (2H, s), 6.68 (1H, d, J_(H,H)=11.8), 7.20-7.64 (9H aromatic+1Hethylenic).

EXAMPLE 3 Z-Styryl 2-Chlorobenzylsulfone

A solution of phenylacetylene (0.02 mol) and 2-chlorobenzyl mercaptan(0.02 mol) and metallic sodium (0.02 g atom) was subjected to theGeneral Procedure to form Z-styryl 2-chlorobenzylsulfide. The titlecompound was obtained in 68% yield following oxidation. ¹HNMR (CDCl₃) δ4.50 (2H, s), 6.65 (1H, d, J_(H,H)=12.0), 7.18-7.74 (9H aromatic+1Hethylenic).

EXAMPLE 4 Z-Styryl 4-Fluorobenzylsulfone

A solution of phenylacetylene (0.02 mol) and 4-fluorobenzyl mercaptan(0.02 mol) and metallic sodium (0.02 g atom) was subjected to theGeneral Procedure to from Z-styryl 4-fluorobenzylsulfide. The titlecompound was obtained in 70% yield following oxidation. ¹HNMR (CDCl₃) δ4.58 (2H, s), 6.62 (1H, d, J_(H,H)=11.86), 7.18-7.60 (9H aromatic+1Hethylenic).

EXAMPLE 5 Z-4-Chlorostyryl Benzylsulfone

A solution of 4-chlorophenylacetylene (0.02 mol) and benzyl mercaptan(0.02 mol) and metallic sodium (0.02 g atom) was subjected to theGeneral Procedure to form Z-4-chlorostyryl benzylsulfide. The titlecompound was obtained in 74% yield following oxidation. ¹HNMR (CDCl₃) δ4.55 (2H, s), 6.66 (1H, d, J_(H,H)=12.12), 7.16-7.65 (9H aromatic+1Hethylenic).

EXAMPLE 6 Z-4-Chlorostyryl 4-Chlorobenzylsulfone

A solution of 4-chlorophenylacetylene (0.02 mol) and 4-chlorobenzylmercaptan (0.02 mol) and metallic sodium (0.02 g atom) was subjected tothe General Procedure to form Z-4-chlorostyryl 4-chlorobenzylsulfide.The title compound was obtained in 76% yield following oxidation. ¹HNMR(CDCl₃) δ 4.62 (2H, s), 6.68 (1H, d, J_(H,H)=11.92), 7.18-7.60 (8Haromatic+1H ethylenic).

EXAMPLE 7 Z-4-Chlorostyryl 2-Chlorobenzylsulfone

A solution of 4-chlorophenylacetylene (0.02 mol) and 2-chlorobenzylmercaptan (0.02 mol) and metallic sodium (0.02 g atom) was subjected tothe General Procedure to form Z-4-chlorostyryl 2-chlorobenzylsulfide.The title compound was obtained in 73% yield following oxidation. ¹HNMR(CDCl₃) δ 4.56 (2H, s), 6.70 (1H, d, J_(H,H)=12.05), 7.18-7.64 (8Haromatic+1H ethylenic).

EXAMPLE 8 Z-4-Chlorostyryl 4-Fluorobenzylsulfone

A solution of 4-chlorophenylacetylene (0.02 mol) and 4-fluorobenzylmercaptan (0.02 mol) and metallic sodium (0.02 g atom) was subjected tothe General Procedure to form Z-4-chlorostyryl 4-fluorobenzylsulfide.The title compound was obtained in 82% yield following oxidation. ¹HNMR(CDCl₃) δ 4.60 (2H, s), 6.70 (1H, d, J_(H,H)=11.78), 7.18-7.60 (8Haromatic+1H ethylenic).

EXAMPLE 9 Z-4-Fluorostyryl Benzylsulfone

A solution of 4-fluorophenylacetylene (0.02 mol) and benzyl mercaptan(0.02 mol) and metallic sodium (0.02 g atom) was subjected to theGeneral Procedure to form Z-4-fluorostyryl benzylsulfide. The titlecompound was obtained in 76% yield following oxidation. ¹HNMR (CDCl₃) δ4.54 (2H, s), 6.68 (1H, d, J_(H,H)=11.94), 7.12-7.58 (9H aromatic+1Hethylenic).

EXAMPLE 10 Z-4-Fluorostyryl 4-Chlorobenzylsulfone

A solution of 4-fluorophenylacetylene (0.02 mol) and 4-chlorobenzylmercaptan (0.02 mol) and metallic sodium (0.02 g atom) was subjected tothe General Procedure to form Z-4-fluorostyryl 4-chlorobenzylsulfide.The title compound was obtained in 82% yield following oxidation. ¹HNMR(CDCl₃) δ 4.60 (2H, s), 6.68 (1H, d, J_(H,H)=11.84), 7.18-7.60 (8Haromatic+1H ethylenic).

EXAMPLE 11 Z-4-Fluorostyryl 2-Chlorobenzylsulfone

A solution of 4-fluorophenylacetylene (0.02 mol) and 2-chlorobenzylmercaptan (0.02 mol) and metallic sodium (0.02 g atom) was subjected tothe General Procedure to form Z-4-fluorostyryl 2-chlorobenzylsulfide.The title compound was obtained in 74% yield following oxidation. ¹HNMR(CDCl₃) δ 4.55 (2H, s), 6.66 (1H, d, J_(H,H)=11.94), 7.20-7.65 (8Haromatic+1H ethylenic).

EXAMPLE 12 Z-4-Fluorostyryl 4-Fluorobenzylsulfone

A solution of 4-fluorophenylacetylene (0.02 mol) and 4-fluorobenzylmercaptan (0.02 mol) and metallic sodium (0.02 g atom) was subjected tothe General Procedure to form Z-4-fluorostyryl 4-fluorobenzylsulfide.The title compound was obtained in 78% yield following oxidation. ¹HNMR(CDCl₃) δ 4.60 (2H, s), 6.65 (1H, d, J_(H,H)=11.83), 7.20-7.65 (8Haromatic+1H ethylenic).

EXAMPLE 13 Z-4-Bromostyryl Benzylsulfone

A solution of 4-bromophenylacetylene (0.02 mol) and benzyl mercaptan(0.02 mol) and metallic sodium (0.02 g atom) was subjected to theGeneral Procedure to form Z-4-bromostyryl benzylsulfide. The titlecompound was obtained in 80% yield following oxidation. ¹HNMR (CDCl₃) δ4.52 (2H, s), 6.80 (1H, d, J_(H,H)=11.98), 7.18-7.59 (9H aromatic+1Hethylenic).

EXAMPLE 14 Z-4-Bromostyryl 4-Chlorobenzylsulfone

A solution of 4-bromophenylacetylene (0.02 mol) and 4-chlorobenzylmercaptan (0.02 mol) and metallic sodium (0.02 g atom) was subjected tothe General Procedure to form Z-4-bromostyryl 4-chlorobenzylsulfide. Thetitle compound was obtained in 87% yield following oxidation. ¹HNMR(CDCl₃) δ 4.58 (2H, s), 6.72 (1H, d, J_(H,H)=12.08), 7.15-7.68 (8Haromatic+1H ethylenic).

EXAMPLE 15 Z-4-Bromostyryl 2-Chlorobenzylsulfone

A solution of 4-bromophenylacetylene (0.02 mol) and 2-chlorobenzylmercaptan (0.02 mol) and metallic sodium (0.02 g atom) was subjected tothe General Procedure to form Z-4-bromostyryl 2-chlorobenzylsulfide. Thetitle compound was obtained in 84% yield following oxidation. ¹HNMR(CDCl₃) δ 4.57 (2H, s), 6.70 (1H, d, J_(H,H)=11.58), 7.18-7.58 (8Haromatic+1H ethylenic).

EXAMPLE 16 Z-4-Bromostyryl 4-Fluorobenzylsulfone

A solution of 4-bromophenylacetylene (0.02 mol) and 4-fluorobenzylmercaptan (0.02 mol) and metallic sodium (0.02 g atom) was subjected tothe General Procedure to from Z-4-bromostyryl 4-fluorobenzylsulfide. Thetitle compound was obtained in 78% yield following oxidation. ¹HNMR(CDCl₃) δ 4.58 (2H, s), 6.65 (1H, d, J_(H,H)=11.78), 7.22-7.67 (8Haromatic+1H ethylenic).

EXAMPLE 17 Z-4-Methylstyryl Benzylsulfone

A solution of 4-methylphenylacetylene (0.02 mol) and benzyl mercaptan(0.02 mol) and metallic sodium (0.02 g atom) was subjected to theGeneral Procedure to form Z-4-methylstyryl benzylsulfide. The titlecompound was obtained in 70% yield following oxidation. ¹HNMR (CDCl₃) δ2.48 (3H, s), 4.60 (2H, s), 6.68 (1H, d, J_(H,H)=11.94), 7.20-7.65 (9Haromatic+1H ethylenic).

EXAMPLE 18 Z-4-Methylstyryl 4-Chlorobenzylsulfone

A solution of 4-methylphenylacetylene (0.02 mol) and 4-chlorobenzylmercaptan (0.02 mol) and metallic sodium (0.02 g atom) was subjected tothe General Procedure to form Z-4-methylstyryl 4-chlorobenzylsulfide.The title compound was obtained in 74% yield following oxidation. ¹HNMR(CDCl₃) δ 2.46 (3H, s), 4.64 (2H, s), 6.75 (1H, d, J_(H,H)=12.21),7.18-7.57 (9H aromatic+1H ethylenic).

EXAMPLE 19 Z-4-Methylstyryl 2-Chlorobenzylsulfone

A solution of 4-methylphenylacetylene (0.02 mol) and 2-chlorobenzylmercaptan (0.02 mol) and metallic sodium (0.02 g atom) was subjected tothe General Procedure to form Z-4-methylstyryl 2-chlorobenzylsulfide.The title compound was obtained in 76% yield following oxidation. ¹HNMR(CDCl₃) δ 2.50 (3H, s), 4.58 (2H, s), 6.80(1H, d, J_(H,H)=11.88),7.20-7.63 (9H aromatic+1H ethylenic).

EXAMPLE 20 Z-4-Methylstyryl 4-Fluorobenzylsulfone

A solution of 4-methylphenylacetylene (0.02 mol) and 4-fluorobenzylmercaptan (0.02 mol) and metallic sodium (0.02 g atom) was subjected tothe General Procedure to form Z-4-methylstyryl 4-fluorobenzylsulfide.The title compound was obtained in 69% yield following oxidation. ¹HNMR(CDCl₃) δ 2.46 (3H, s), 4.62 (2H, s), 6.78 (1H, d, J_(H,H)=11.98),7.18-7.59 (9H aromatic+1H ethylenic).

EXAMPLE 21 Effect of Z-Styryl Sulfones on Breast, Prostate and OvarianTumor Cell Lines

A. Cells.

The effect of the Z-styryl sulfones on normal fibroblasts and on tumorcells of breast, prostate and ovarian origin was examined utilizing thefollowing cell lines: breast tumor cell lines: MCF-7, BT-20 and 435;prostate tumor cell lines LnCaP and DU-145; and ovarian tumor cell linesOVCAR and SKOV3. NIH/3T3 and HFL cells, which are normal murine andhuman fibroblasts, respectively, were also tested. LnCap is anandrogen-dependent prostate tumor cell line. MCF-7 is anestrogen-responsive breast tumor cell line, while BT-20 and 435 areestrogen-unresponsive breast tumor cell lines. MCF-7, BT-20 and 435 weregrown in Dulbecco's modified Eagle's medium (DMEM) containing 10% fetalbovine serum supplemented with penicillin and streptomycin. LnCaP andDu145 were cultured in RPMI with 10% fetal bovine serum containingpenicillin and streptomycin. NIH3T3 and HFL cells were grown in DMEMcontaining 10% calf serum supplemented with penicillin and streptomycin.All cell cultures were maintained at 37° C. in a humidified atmosphereof 5% CO₂.

B. Treatment with Z-Styryl Sulfones and Viability Assay

Cells were treated with test compound at 2.5 micromolar concentrationand cell viability was determined after 72 hours by the Trypan blueexclusion method. The results are set forth in Table 1.

Activity for each compound is reported as a range of cell induced death(% Death) with the lowest activity in the range of 10-20% and thehighest being above 75%. For each compound tested, the activity wasfound to be in the same range for the three cell types.

Two of the twenty compounds tested (Examples 8 and 14) had kill rates ofover 75%; three compounds (Examples 6, 10, and 16) had rates of 60-70%.

The five compounds exhibiting the highest activity contained halogen inthe 4-position in Formula I.

Normal cells HFL and NIH 3T3 were treated with the same compounds inTable 1 under the same conditions of concentration and time. The normalcells were not killed.

TABLE 1 Effect of (Z)-styryl benzyl sulfones on tumor cells Tumor celltype Ex. R₁ R₂ R₃ R₄ Breast Prostate Ovarian  1 H H H H − − −  2 H H HCl + + +  3 H H Cl H + + +  4 H H H F + + +  5 H Cl H H + + +  6 H Cl HCl +++ +++ +++  7 H Cl Cl Cl + + +  8 H Cl H F ++++ ++++ ++++  9 H F HH + + + 10 H F H Cl +++ +++ +++ 11 H F Cl Cl + + + 12 H F H F ++ ++ ++13 H Br H H + + + 14 H Br H Cl ++++ ++++ ++++ 15 H Br Cl Cl + + + 16 HBr H F +++ +++ +++ 17 H CH₃ H H + + + 18 H CH₃ H Cl + + + 19 H CH₃ ClCl + + + 20 H CH₃ H F + + + The activity of the compounds at 2.5micromolar after 72 hours. Breast cell lines: MCF-7, BT-20, 435 Prostatecell lines: LnCaP, DU-145 Ovarian cell lines: OVCAR, SKOV3 10-20% Death= − 20-25% = + 40-50% = ++ 60-70% = +++ above 75% = ++++

EXAMPLE 22 Effect of Z-Styryl Sulfones on Lung, Renal and Brain TumorCell Lines

The procedure of Example 21 was followed for certain of the(Z)-benzylsulfones, substituting the following cancer cell lines: lung,N417 and H157; renal, CAKI-1 and CAKI-2; glioma, U87 and SW1088. Theresults are set forth in Table 2.

TABLE 2 Effect of (Z)-styryl benzyl sulfones on tumor cells Tumor celltype Ex. R₁ R₂ R₃ R₄ Lung Renal Glioma  5 H Cl H H + + +  6 H Cl H Cl+++ +++ +++  7 H Cl Cl Cl + + +  8 H Cl H F ++++ ++++ ++++ 10 H F H Cl+++ +++ +++ 11 H F Cl Cl + + + 12 H F H F ++ ++ ++ 14 H Br H Cl ++++++++ ++++ 15 H Br Cl Cl + + + 16 H Br H F +++ +++ +++ 18 H CH₃ HCl + + + 20 H CH₃ H F + + + The activity of the compounds at 2.5micromolar after 72 hours. Lung cell lines: N417, H157 Renal cell lines:CAKI-1, CAKI-2 Glioma cell lines: U87, SW1088 10-20% Death = − 20-25%= + 40-50% = ++ 60-70% = +++ above 75% = ++++

All references cited with respect to synthetic, preparative andanalytical procedures are incorporated herein by reference.

The present invention may be embodied in other specific forms withoutdeparting from the spirit or essential attributes thereof and,accordingly, reference should be made to the appended claims, ratherthan to the foregoing specification, as indication the scope of theinvention.

What is claimed is:
 1. A method of treating an individual for cancercomprising administering to said individual an effective amount of acompound according to the formula:

wherein R₁ is selected from the group consisting of hydrogen, chloro andnitro; R₂ is selected from the group consisting of hydrogen, loweralkyl, lower alkoxy, chloro, bromo, and fluoro; and R₃ and R₄ areindependently selected from the group consisting of hydrogen, loweralkyl, nitro, chloro, bromo, and fluoro; provided at least one of R₁ orR₂ is hydrogen, wherein the cancer is selected from the group consistingof ovarian, breast, prostate, lung, renal and brain cancers.
 2. A methodfor inducing apoptosis of tumor cells in an individual afflicted withcancer, comprising administering to said individual an effective amountof a compound according to the formula:

wherein R₁ is selected from the group consisting of hydrogen, chloro andnitro; R₂ is selected from the group consisting of hydrogen, loweralkyl, lower alkoxy, chloro, bromo, and fluoro; and R₃ and R₄ areindependently selected from the group consisting of hydrogen, loweralkyl, nitro, chloro, bromo, and fluoro; provided at least one of R₁ orR₂ is hydrogen, wherein the tumor cells are selected from the groupconsisting of ovarian, breast, prostate, lung, renal and brain tumorcells.
 3. A method according to claim 1 wherein R₃ is hydrogen; and R₂and R₄ are independently selected from the group consisting of chloro,fluoro and bromo.
 4. A method according to claim 2 wherein R₃ ishydrogen; and R₂ and R₄ are independently selected from the groupconsisting of chloro, fluoro and bromo.
 5. A method according to claim 1wherein the cancer is breast cancer.
 6. A method according to claim 1wherein the cancer is prostate cancer.
 7. A method according to claim 2wherein the tumor cells are breast tumor cells.
 8. A method according toclaim 2 wherein the tumor cells are prostate tumor cells.
 9. A methodaccording to claim 3 wherein the compound is Z-4-chlorostyryl4-chlorobenzylsulfone.
 10. A method according to claim 3 wherein thecompound is Z-4-chlorostyryl 4-fluorobenzylsulfone.
 11. A methodaccording to claim 3 wherein the compound is Z-4-fluorostyryl4-chlorobenzylsulfone.
 12. A method according to claim 3 wherein thecompound is Z-4-fluorostyryl 4-fluorobenzylsulfone.
 13. A methodaccording to claim 3 wherein the compound is Z-4-bromostyryl4-chlorobenzylsulfone.
 14. A method according to claim 3 wherein thecompound is Z-4-bromostyryl 4-fluorobenzylsulfone.
 15. A methodaccording to claim 4 wherein the compound is Z-4-chlorostyryl4-chlorobenzylsulfone.
 16. A method according to claim 4 wherein thecompound is Z-4-chlorostyryl 4-fluorobenzylsulfone.
 17. A methodaccording to claim 4 wherein the compound is Z-4-fluorostyryl4-chlorobenzylsulfone.
 18. A method according to claim 4 wherein thecompound is Z-4-fluorostyryl 4-fluorobenzylsulfone.
 19. A methodaccording to claim 4 wherein the compound is Z-4-bromostyryl4-chlorobenzylsulfone.
 20. A method according to claim 4 wherein thecompound is Z-4-bromostyryl 4-fluorobenzylsulfone.
 21. A method oftreating an individual for leukemia, comprising administering to saidindividual an effective amount of a compound according to the formula:

wherein R₁ is selected from the group consisting of hydrogen, chloro andnitro; R₂ is selected from the group consisting of chloro, bromo, andfluoro; R₃ is hydrogen; and R₄ is selected from the group consisting ofchloro, bromo, and fluoro; provided at least one of R₁ or R₂ ishydrogen.
 22. The method of claim 21, wherein the compound isZ-4-fluorostyryl-4-chlorobenzyl sulfone.